1. Field of the Invention
This invention relates to a method of and apparatus for grinding a rabbet in a glass sheet and more particularly for grinding a rabbet in the peripheral edge of a glass sheet.
2. Discussion of the Technical Problems and the Prior Art
Rabbets are formed on the peripheral edges of glass sheets to seat the glass sheets in window frames, for example, window frames of aircrafts. Care has to be exercised when a rabbet is ground in a glass sheet to prevent the glass sheet from overheating. The heat is generated by friction between the grinding wheel and glass sheet. The frictional heat may crack the glass sheet, change the stress pattern in the glass sheet and/or melt the glass sheet in the grinding area.
The prior art teaches apparatus for beveling glass edges for example, U.S. Pat. No. 247,751; for removing blow over in glass jars, e.g., U.S. Pat. No. 99,160; and for grinding edges on glass sheets, for example, U.S. Pat. Nos. 2,022,530; 2,782,569; 2,795,086; 2,826,872; 3,641,711; and 3,827,198.
Although the apparatus taught in the above-identified patents are suitable for their particular application, there is no teaching in any of the patents of grinding a rabbet in the edge of a glass sheet.
It would be advantageous therefore to provide a method of and apparatus for grinding a rabbet in a glass sheet that does not thermally or mechanically damage the glass sheet.